This is the corner of a lift motor room that has a wooden extension. The woodwork adds no strength to the brickwork of course. Most masonry fixings rely on an expansion force within the brick, and this means that the brick needs to be surrounded by other bricks and strong mortar. This is especially true of soft bricks

“How do you tell whether the brick is soft or hard?”

“Because you can drill a soft brick much more easily than a hard one, you dummy!”

Never fit expansion bolts into bricks that aren’t surrounded by other bricks. Never use the top four courses of a wall. Never use a narrow pillar between apertures such as windows. Be wary of single leaf walls. And obviously, don’t attempt to fix to a wall that looks ready to fall down!